A botnet is a network of infected computers with malwares. Most of the internet users do not even realize that their computers are attacked by botnet. Botnet can do different types of attacks using your IP address and at the same time your PC becomes a remote control robot for illegal activities. Botnet generally connect through bots, an infected network which takes the control of the entire system remotely. This robot can give information to other spams also. A botnet attacker gets control of your computer in many ways through virus or worms. Botnets are powerful because the hackers control thousands and sometimes lakhs of computers remotely to perform some illegal activities online. Hackers use botnets to make a machine unavailable to its users temporarily while others use them as a spam.
Types of Botnets
The attacks of Botnets has become major problem globally and they are spreading very vast through all systems. Botnet can be done in two ways in which one is direct method and other is indirect method. Direct method means botnet establishes a connection directly to the computers which are infected by cyber criminals and manages it by using bot program. The other way is indirect method in which the control center is connected by a bot and sends a request or spam to the user & then performs the returned command. Botnets can be centralized in which computers are connected in a single direction to the control center whereas the other is decentralized where there is a bot to bot connection.
Bot Master or Botnet Herder
‘Bot master’ also called as ‘Botnet Herder’ is an individual server that keeps several PCs under control by installing a malicious software. Botnet servers also communicates with other botnet servers which are under the control of bot master and maintains the network. These herds of bot machines behave as zombies working for the bot masters, attacking or infecting the computers through a network. Once the PC is infected, the system acts weirdly, suddenly it shuts down, strange emails appear in your mailbox, files may get corrupted or you may get unknown error message.
The infected machines forms a network called as ‘zombies’.A bot uses a zombie network that downloads another malicious programs to steal the passwords & are sold out for infecting web pages to enlarge zombie network. Zombie army also referred as malware botnet. It is under the control of remote that directs it. Zombies spread through email spam and run secretly in the background generating fake clicks.
Spamming through Botnet
Instead of targeting the criminal activity directly, some Botnet owners give it on rent to the spammers, which allows them to to send thousands of messages from infected machines within a short period of time. Most of the mail servers blacklist or block the spam automatically whereas spammers overcome this problem by sending more and more emails to the unknown users. It not only attacks the computers but will collect the email address information from computers which are infected. Botnet will add more and more new email addresses and spreads across faster from one system to another. Sometimes botnet also attack the servers making them unavailable by sending false requests from the bot infected PCs.
Distributed denial of service attack
A malware infected computer is more vulnerable to become a part of DDos attack. It is called as distributed denial of service. At the same time it can also perform other activities like malicious actions making the network unavailable to the users. It uses a single machine which targets a software by sending requests. Through remotely controlled network of control servers, Botnet executes the DDos attack on the website servers, making the websites completely unavailable to the users.